Monoazo beta-resorcylic acid dyes



United States Patent This invention relates to new dyes; and, more particularly, it is concerned with compounds which are especially suitable for dyeing shaped articles of polypropylene and other thermoplastic resins, such as polyesters, polyacrylics, polyamides and other polyolefins.

In the past, many classes of dyes have been applied to shaped articles, such as synthetic fibers, in an attempt to dye these articles in a commercially satisfactory way, that is to say, to yield a brilliant dyed product which is fast to light, washing and dry cleaning. However, these classes of dyes have not been entirely suitable since the articles dyed therefrom have had a relative poor fastness to light,

washing or dry cleaning, or they have had inadequate brilliance.

An object of the present invention is to obtain dye compositions which are suitable for dyeing polypropylene and other polyolefins to provide and end product with superior fastness properties and wit-h excellent brilliance and tinctorial value.

Another object of the invention is to obtain dyes which can be used for dyeing other thermoplastic resins, such as polyesters, polyacrylics, and polyamides to form a dyed article having excellent fastness to light, washing and dry cleaning and having exceptional brilliance.

It is common practice in the textile industry to form composite fabrics containing two or more types of fibers. For example, the composite fabric may be woven of threads containing, in a predetermined pattern, threads of polypropylene, nylon, and/ or other fibers, such as polyacrylics, natural fibers, etc. With respect to these composite fabrics, there is an immediate problem of finding .a dye which will give a union dyeing. This a problem and a term which is well-known in the art.

Accordingly, another object of this invention is to produce dyes which will dye simultaneously and satisfactorily mixed fabrics composed of more than one synthetic and/or wool and silk fibers.

A further object of the present invention is to provide 'dyes which are fast to washing and severe dry cleaning when applied to shaped articles, particularly fibers containing finely dispersed metallic compounds and, more specifically, to provide dyes of extraordinary brilliance and tinctorial value.

One of the very difficult problems that has confronted the industry is stabilizing polypropylene and other polyolefin fibers against ageing, that is degradation caused by exposure to air, light, and/or heat. Many types of known stabilizers have been incorporated into the fibers to impart some degree of stability thereto. However, these stabilizers generally are removed by Washing and/ or dry cleaning with various solvents, and the fibers lose most or all of their resistance to ageing.

Accordingly, still another object of this invention, is to stabilize shaped articles formed from polypropylene and other polyolefins and preferably simultaneously stabilize and pigment such materials.

Another object is to improve stability and [-l16 'l'6SlSiance of these polymers to ageing, particularly after they have been washed, dry cleaned or exposed to other solvents.

Other objects and advantages of the present invention will appear from the following description.

According to the present invention, it has been found that certain monoazo beta-resorcylic acid compounds con- 3,257,373 Patented. June 21, 1966 fer exceptional brilliance and excellent washing and dry cleaning stability when they are dyed on thermoplastic shaped articles of polyolefins, particularly polypropylene containing a metal; polyamides; and polyacrylics. These monoazo beta-resorcylic acid compounds are described by the following structural formula:

( n OH R COOH wherein each X is a substituent group attached to the benzene nucleus independently selected from the class consisting of C to C alkyl, cyclo alkyl having up to 6 carbon atoms, halogen, carbacyl having up to 6 carbon atoms, benzoyl, N-alkyl sulfonamido said alkyl containing 1-5 carbon atoms, N,N-dialkyl sulfonamido each of said alkyls containing 1-5 carbon atoms, alkoxy containing 1-4 carbon atoms, trifiuoromethyl, cyano, benzoylamino, phenylamino, carboalkoxy containing l-4 carbon atoms, dialkylamino each of said alkyls containing l-S carbon atoms, beta cyano ethyl oxy, beta hydroxy ethyl oxy, alkyl sulfonyl containing 1-4 carbon atoms, hydroxy alkyl sulfonyl containing 1-4 carbonatoms, di(beta hydroxy ethyl) amino, di(beta cyano ethyl) amino, 2,3- benz-, carbonamido and phenyl; R is a substituent group attached to the benzene nucleus selected from the group consisting of hydrogen and a halogen; and a is an integer from 1 to 5 inclusive.

The foregoing groups may be substituted with simple substit-uents recognized in the dyeing art such as methyl, halogen, methoxy and other lower alkoxy groups (containing 1 to 5 carbon atoms), trifiuoromethyl car-bonamido, etc.

Preferred monoazo beta-resorcylic acid compounds are found among those in which the group or groups X include at least one lower alkyl, that is 1 to 4 carbon atoms such as methyl, or such compounds in which the group or groups X include at least one trifluoromethyl group, or at least one halogen (fluorine, chlorine, or bromine), or at least one lower alkoxy group (1 to 4 carbon atoms),

or monoazo beta-resorcylic acid compounds in which the group or groups X include the 2,3-benz group, that is naphthaleneazo-beta-resorcylic acids.

The desirable properties of the compounds described above are realized by reacting them with a metallic compound of aluminum or zinc. The reaction product is generally formed in the shaped articles, such as fibers of polypropylene and other polyolefins, by incorporating initially a metal compound of aluminum or zinc into the polyolefin. This procedure will be described more completely hereafter.

The precise nature and structure of the aforementioned reaction product is not clearly understood. However, it is thought that a chelate ring or linkage may be formed between the metallic cation and the adjacent carboxylic and hydroxyl groups on the beta-resorcylic acid ring, and this may be responsible for the desirable properties of the formed reaction product. Furthermore, there is no precise stoichiometric ratio between the dye and the metallic compound. This is believed to be due to any one or more of a number of factors. In the first place, the metallic compound may not penetrate into all of the interstices of the dye or vice-versa; and, therefore, the reaction may not be complete. In the second place, aluminum and zinc are known to exist in the form of polymers or oligomers; and, therefore, a single dye molecule may account for more than one atom of the metal. The amount of dye used may be suificient to account for all of the metal present; however, this is not an absolute requirement. For instance, in dyeing shaped articles, such 3 as fibers, it may not be necessary to provide enough dye to react with all of the metal which is finely divided and uniformly distributed throughout the mass. Furthermore, the ratio of fiber to metal isv not a critical feature of the invention and a suitable ratio may be readily determined from a given set of circumstances and the desired objectives.

A particularly striking feature of this invention is the stabilizing effect of the monoazo beta-resorcylic acid compounds 011 the polypropylene or other polyolefin shaped article, such as a fiber. As stated heretofore, stabilizing such materials has been a very difi'icult problem, particularly since laundering, dry cleaning or exposure to other solvents tend to remove known stabilizers. It has been surprisingly found in accordance with the present invention that the monoazo beta-resorcylic acid compounds described above impart stability to the polypropylene or other polyolefin and resist removal by laundering, dry cleaning, etc.

The aforementioned dyes may be prepared by various methods. They are preferably formed by coupling a substituted aniline through diazotization with beta-resorcylic acid in an alkaline solution. However, decarooxylation occurs during the coupling reaction. In order to obtain outstanding fastness properties, the dyed fiber 'has to have considerable washing; alternatively, the dyestuff may be purified with sodium carbonate, sodium bicarbonate or the like to remove the insoluble decarboxylated by-product.

In one embodiment, a shaped article, for example, a synthetic fiber, has a metal incorporated therein before a monoazo beta-resorcylic acid compound is applied. The synthetic fibers or other shaped article applicable to this invention include polyolefins, polyesters, for'example, condensation products of polybasic acids with polyhydric alcohols and dacron; polyamides, such as nylon; polymers of acrylic acid compounds, such as acrylonitrile; and polymers of vinyl compounds, such as vinyl alcohol, vinyl chloride and styrene. A polyolefin, which is the preferred polymer for a synthetic fiber, includes the following polymers among others: polyethylene, polypropylene, polybutene, poly-3-methyl-butene-l, polypentene, poly-4-methylpentene-1, and polyheptene. The polyolefin, e.g., polypropylene, can be prepared by any known method. A suitable, but not the only method, is disclosed in the Belgian Patent No. 533,362, which is incorporated herein by reference.

Synthetic shaped articles are formed from the afore mentioned thermoplastic polymers in accordance with known prior art procedures. A fiber, which is preferred, is defined herein as any fibrous unit, for instance, filament yarns, mats, staple yarns, rovings, sheets, rods, plates, woven fabrics and chopped fibers. The following exemplify specific commercial fibers which can be employed herein: Spun Dacron T-54; Nylon Filament Thread; Cresland T58; Acrilan 1656; and Polypropylene 805 Fiber.

Although synthetic fibers are usually employed, the reaction product between metallic material and beta-resorcylic acid compound'is also applicable to natural fibers, for example, wool, animalized cotton and silk. Furthermore, it is also possible to use a combination of any two or more synthetic or natural fibers to form a composite fabric. Union dyeing is provided on the composite fabric by using the monoazo dyes described herein.

The metal, which is incorporated into the fiber, forms a reaction product with the subsequently applied dye composition. Aluminum and zinc are the preferred metals, and they are utilized as metallic compounds. Organic metal salts, which are preferred, may be employed within the range of .02 to 2% based upon the weight of the fiber. Carboxylic acid metal salts with 6 to carbon atoms, which are suitable for this. invention, include aluminum stearate, zinc stearate, aluminum laurate, and the aluminum salt of 2-ethyl hexanoic acid. These salts are intimately dispersed throughout the polymer at any stage prior to its extrusion. An efiicient blending apparatus is usually adequate to. accomplish this result. After dispersion, the blend may be extruded at the fluid temperature for the polymer, that is, 250 to 350 C. for polypropylene. Accordingly, the metal is usually distributed uniformly throughout the fiber, such as, 'polyolefin fiber, which provides complete penetration of the dye from the dye bath into the fibers. By way of illustration, the incorporation of the metal salt in the polymer may be made by mixing 10 parts of the powder of the salt with parts of the powder of the polymer to an intimate and uniformly dispersed mixture. This mixture may be extruded to form a concentrate which subsequently is finely divided again and intimately blended with additional polymer to obtain the desired low concentration of metal for extrusion to the shaped product.

The monoazo beta-resorcylic acid compounds heretofore described form the basis of an aqueous dye bath into which the fibers are immersed. Since the dyes are insoluble in water, they are dispersed or emulsified in the bath! The concentration of the dye bath can vary over a wide range, depending upon the depth of shade desired. Any known dyeing technique can be employed in this invention. For example, a skein can be simply immersed into the bath at its approximate boiling temperature; or a finished piece can be dyed by using a jigger. The dye bath can be slightly acidic and the fiber is usually rinsed and dried subsequent to its immersion in the dye bath. Known pressure dyeing techniques which accelerate the entry of the dye into the fiber may also be used.

In another embodiment of the present invention, the fiber, such as a synthetic or natural fiber, is not modified with a metallic material. This unmodified fiber is immersed directly into a dye bath and subsequently rinsed and dried. These steps can be accomplished by any procedure known in the art and can be similar to the procedures described for the above embodiment. For example, the aqueous dye bath suspension can contain a sulfonated oil, soap, sodium lignin sulfonate, or other suitable dispersing agent. Although direct dyeing operations are generally performed at temperatures of about to 212 F., any suitable temperature can be used, including pressure dyeing and thermofixation techniques. The fiber to be dyed is usually added to the dye bath initially at a relatively low temperature and then a higher temperature is provided for carrying out the actual dyeing operation. The intensity of dyeing is varied by changing the proportion of the weight of dye to the weight of the fiber.

Thus, in accordance with the instant invention monoazo beta-resorcylic acid compounds have been provided which are suitable dyestuffs. Furthermore, these compounds will react with metal-modified shaped articles to form a dyed end product which has excellent brilliance and tinctorial value and which is also fast to light, dry cleaning and Washing. Similarly, these compounds can be applied directly to dye an unmodified fiber, for example, nylon, polyester, and acrylic fibers have -polar groups which can form a polar linkage with the present dyes to improve the receptivity of the dye and the fastggs properties, such as light fas-tness of the dye on the ers.

In still another embodiment of the invention, the monoazo beta-resorcylic acid compound described above is reacted with the metallic compound in solution without the necessity of any shaped article such as fiber being present, to form a pigment which can be recovered and used as a pigment in a manner known in the art. The reaction conditions and ratios of reactants in this embodiment of the invention are substantially the same as those described above for the dyeing of fibers.

The following examples are submitted to illustrate but not to limit this invention. Unless otherwise indicated,

all parts and percentages in the specification are based upon weight.

EXAMPLE I A 3-chlorobenzeneazo-beta-resorcylic acid dyestuff was provided by dissolving 46.3 parts (.3 mol) of beta-resorcylic acid in 900 parts of water containing 49.2 parts (6 mols) of sodium acetate and 12 parts (.3 mol) of sodium hydroxide to form a first solution.

A separate solution was prepared from 38.2 parts (.3 mol) of m-chloroanilien and 1000 parts of water containing 85.5 parts (.9 mol) of concentrated hydrochloric acid. This solution was cooled to 5 C. with the subsequent addition of 110 parts of a 20% sodium nitrite solution (.315 mol). After stirring for one hour and filtering, a clarified second solution was formed.

This second solution was added to the first solution over a period of 2 hours at-14 C. to form an alkaline reaction system. After the diazotization was completed, the dyestuff product therefrom was filtered, and washed free of salts.

The vat presscake was then reslurried in 2000 parts of water containing 50 parts of sodium bicarbonate. This slurry was heated to 60 C. and filtered to remove the decarboxylated by-products. The dyestuff was recovered from the filtrate by making acidic to a pH of 6. After subsequent filtering, the presscake was dispersed to a 10% aqueous paste.

Fiber grade polypropylene, which was blended intimately and uniformly with 0.080 wt. percent of aluminum monostearate, was used 'to manufacture 4 /2 denier crimped staple fiber by melt extruding, stretching, crimping and cutting to a 2 in. length. This cut fiber was subsequently carded and spun to produce yarns approximating .10s single (cotton system) count. Convenient sized skeins were then reeled from this yarn.

A sample containing ten grams of skein was provided. This. sample was immersed in a 500 cc. dye bath at 120 F. The bath consists of an aqueous dispersion of 0.6 gram of the dry aforementioned dyestulf. Prior to the entry of the yarn, sufiicient acetic acid was added to the dye bath to provide a pH of 6.0. The dyeing was accomplished by gradually raising the temperature of the dye bath to its boiling point during a 30 minute period. The skein was frequently turned with a glass stirring rod and the temperature was maintained at 212 F. for a period of one hour. The yarn was then removed from the dye bath and thoroughly rinsed in running water at 160 F. The skein was subsequently scoured by turning it for 30 minutes at 160 F. in a 400 cc. aqueous bath containing /2% of Triton X-100 (iso-octyl-phenyl poly ethoxy ethanol) and /2% of sodium carbonate. A thorough rinse was subsequently performed in running water at 110 F.

The dyed sample was then subjected to the following tests.

( 1) Color fastness to dry cleaning: Tentative Test Method 85-1960 (1960 Technical Manual of the American Association of Textile Chemists and Colorists, pages 88-9), amended as follows: the temperature shall be (5) Color fastness to oxides of nitrogen in the atmosphere (gas fading): Three cycles were used of Standard Test Method 23-1957 (page 98 loc. cit.) or Standard Test Method 75-1956 (page 100 loc. cit.).

(6) Sublimation and heat fastness tests: Sublimation and heat fastness tests were run at 265 F. for minutes.

The dyed polypropylene herein had a green yellow hue and was extremely fast to washing, dry cleaning, gas

115 F.; the time shall be 1 hour; and the amount of Test III-A being used for polyester and after-chromed nylon and Test II-A for nylon. (4) Color fastness to light: AATCC Standard Test Method 16A, 1960 (page 90 Ice. cit.).

fading, sublimation and light.

EXAMPLE II A Dacron fiber was dyed with the dye of Example I by providing a bath at F. containing 200 parts water and 1.5 parts of a blend of 67% biphenyl and 33% anionic emulsifier. Ten grams of skein were incorporated fora five to ten minute run. The aforementioned dye, which had been previously pasted and dispersed in 100 parts water, was added and the temperature of the bath was raised to boil for 1 to 1 /2 hours. The following procedures were subsequently employed; rinsing for 5 minutes in afresh bath heated .as rapidly as possible to to 200 F.; dropping without cooling; and scouring at 200 F. for 15 to 20 minutes.

The dyed Dacron fiber was a brilliant orange and it was fast to washing, dry cleaning and light.

EXAMPLE III The compounds indicated in Table I include the dye described in the previous Examples and those dyes which were prepared by comparable procedures with the react ants being varied to form the desired end product. Polypropylene and Dacron fibers were dyed with certain compounds as per Example I and the resultant shades are also indicated in Table I. All of the dyed products had good fastness to washing and dry cleaning.

Table I OH 5 6 I C O O H Dye No A-Ring Substituents Shade on Shade on Polypropylene Dacron 1-..- 3-OFh Or Brilliant Orange. 2 2-C Neural Yellow". Red Gold.

Green Yellow. Brilliant Orange. 2-C1;5-CF3 3-OH3O 2,5-di-Cl Do. 4-(p-CHaOCtH4NH) Gold Having set forth the general nature and specific embodiments of the present invention, the scope is now particularly pointed out in the appended claims.

We claim:

1. A dye having the structure:

wherein each X is a substituent group attached to the benzene nucleus independently selected from the class consisting of C to C alkyl, chloro, bromo, fluoro, carbacyl having up to 6 carbon atoms, alkoxy containing 1-4 carbon atoms, trifiuoromethyl, phenylamino, and 2,3- benz-; and a is an intger from 1 to 5 inclusive.

2. A dye composition Which is 3-chlorobenzeneazo-betaresorcylic acid.

7 3. A dye composition which is Z-trifluoromethylbenzeneazo-beta-resorcylic acid. 3

4. A dye composition which is 3-methoxybenzeneazobeta-resorcylic acid. I

5. A dye compoisition which is naphthaleneazo-betaresorcylic acid.

6. A dye composition which is 2,5-dich1orobenzeneazobeta-resorcylic acid.

7. A dye composition which is 3-methylbenzeneazobeta-resorcyiic acid.

8. A dye composition which is Z-chloro-S-trifluoromethylbenzeneazo-beta-resorcylic acid.

9. A dye composition which is 4-(p-methoxyphenylamino)-benzeneazo-beta-resorcylic acid.

10. A dye composition which is 4-acetylbenzcneazobeta-resorcylic acid.

References Cited by the Examiner UNITED STATES PATENTS 431,297 7/1890 Walter 260 207 528,965 11/1894 Muhlert 260 207 2,302,955 11/1942 Raiziss et a1. 260196 2,516,303 7/1950 Dickey 260-196 X 2,717,823 9/1955 Lowe 260205 x 2,759,921 8/1956 Schmid et a1 260205 X 2,776,957 1/1957 Brentano et a1. 260207 x 2,867,494 1/1959 Streck 842 2,877,219 3/1959 U666 et a1. 260-196 2,893,814 7/1959 Streck 8-42 15 CHARLES B. PARKER, Primary Examiner. 

1. A DYE HAVING THE STRUCTURE: 